La(Ⅲ)和Co(Ⅱ)复合掺杂非晶态氢氧化镍的电化学性能研究

Study on Electrochemical Performance of Amorphous Nickel Hydroxide Codoped with La(Ⅲ) and Co(Ⅱ)

关键词:  氢氧化镍  电化学性能  复合掺杂

Key words:  nickel hydroxide  electrochemical performances  codoped

摘要:

采用微乳液快速共沉淀法制备出稀土La(Ⅲ)和Co(Ⅱ)复合掺杂非晶态氢氧化镍粉体,采用XRD、SAED和Raman光谱测试分析其结构形态和形貌,将样品合成镍电极材料并组装成MH-Ni电池,研究样品电极的不同掺杂比例对其电化学性能的影响及其相应的电化学效应作用。结果发现,样品材料的微结构无序性强,质子缺陷较多,呈现明显非晶材料结构特征;在80 mA·g^-1恒电流充电5h,40 mA·g^-1恒电流放电,终止电压为1.0 V的充放电制度下,复合掺杂4 wt.% La(Ⅲ)2 wt.% Co(Ⅱ)样品的放电平台为1.273 V,放电容量高达348.43mAh·g^-1,电极材料在充放电循环30次,放电比容量衰减率仅为2.86%,循环可逆性较好。

Abstract:

Amorphous nickel hydroxide codoped with rare earth La (Ⅲ) and Co (Ⅱ) has been synthesized by the method of micro-emulsion.The microstructure and morphology of the sample were characterized by XRD, SAED and Raman, the results showed that the sample with codoped La (Ⅲ) and Co (Ⅱ) was amorphous and the disordering degree was strong.The electrochemical properties were tested by using a simulated MH-Ni battery where amorphous nickel hydroxide was used as active material.Electrochemical performances of the adulterated electrodes have been tested at different doping proportional quantities.The effect and corresponding mechanism of the electrochemical performances of some factors have been studied.The experimental results showed that the specific capacity of the sample codoped with 4wt.%La (Ⅲ) and 2wt.%Co (Ⅱ) was 348.43 mAh·g^-1 and discharge plateau potential was 1.273 V at 80 mA·g^-1 charge current, 40mA·g^-1 discharge current and cut-off potential of 1.0 V.After 30 cycles the capacity only decreased 2.86%, the cyclic of sample electrode was reversible.